The hot-water boiler in common use, such as shown in Fig. 268, has four openings, two at the top, one at the bottom, and one on the side. Into the latter, the hot water or flow pipe from the water front is connected. The connection shown in Fig. 268 is made under favorable conditions, the water front being at such height that a good rise can be obtained between the range and boiler, the range being located in close proximity to the boiler. The latter is a condition always to be desired, but not always to be obtained.
With a short range connection, there is less loss from friction of pipe and fittings, and less loss of heat than would result in the use of a long flow pipe.
In the use of a long flow pipe there is also much greater danger of a dip or sag in the pipe, and greater danger that it will pitch in the wrong direction. The tendency of hot water being upward, the greatest care should be taken that the flow pipe from the range pitches upward at all points.
Fig. 269. - Flow Pipe of Range Connection Pitching in Wrong Direction.
The connection shown in Fig. 269 will at once be seen to be a very poor piece of work, from which satisfactory results cannot possibly be expected.
It is a very common error, however, to run the flow with a pitch in the wrong direction. The best practice in the construetion of range connections, calls for the use of 45-degree elbows. Their use is shown in the illustration of Fig. 270. The advantage gained is due to a decrease in the friction of the water in passing through a pipe so provided. The path for the hot water made by the flow pipe of Fig. 270, is clearly much more smooth than it would be if the bends were made abruptly by means of the common 90-degree bends or elbows.
In constructing the range connection, provision should always be made for drawing off the contents of the boiler without the necessity of disconnecting any part of the connection. This is accomplished by the use of a sediment cock, as shown in Fig. 268. A common bibb is generally used for this purpose, and it should be located at the lowest point in the range connection, in order that all the water in the boiler and in the range piping may be drawn off. In order to make the water flow out of the boiler, it is necessary to exert atmospheric pressure upon the contents of the boiler, and this is generally done by opening a bibb on a floor above the boiler, or by disconnecting one of the boiler couplings at the top of the boiler. The objection to the use of the sediment cock as the only means of draining the boiler, is that the water must be disposed of by drawing it off into pails, which is naturally a long and tedious undertaking.
Fig. 270. - Use of 45 Degree Elbows on Range Connections.
In Fig. 271 is shown a method of draining the boiler into a convenient fixture trap, usually that of the kitchen sink. This method consists in running a wrought-iron or lead waste from the cold-water range pipe, and providing the connection with a stopcock. When the stop cock is opened, the contents of the boiler quickly pass off into the drainage system, through the trap to which the draw-off pipe is connected.
Fig. 271. - Drainage of Boiler into Sink Trap, - Poor Practice.
This method, however, is not to be considered good practice, as by means of it, direct connection is made between the water supply and drainage systems. These two systems should not be directly connected in this instance or in any other instance. The connection of the boiler waste into the kitchen sink trap is a very common one. on old-style work, but is in general practice but little at the present time. Another somewhat similar method of draining the range boiler is that of Fig. 272, in which the connection is made into the drainage system, the waste pipe being served by its own trap. This is open to the same objections that apply to the work of Fig. 271.
The proper method of providing drainage for the range boiler is to be seen in Fig. 273. In this case, the boiler waste is conducted into an open fixture, the laundry tubs in the basement. Such a method, while providing fully for the drainage of the boiler, avoids direct connection into the drainage system. There often collects in the bottom of the range boiler a very heavy body of rust and sediment, which also often collects in the range connection, sometimes almost entirely filling it. The water front becomes filled with sediment very often also. When the latter occurs, the water front must be taken out and cleaned. A very effective method of doing this work is to heat the water front over a hot fire. If possible to heat it over a forge the work can be done most effectively and easily. This dries the sediment, and that which does not crack and flake off can usually be dislodged by means of a rod or by hammering the casting.
Fig. 272. - Drainage of Boiler into Drainage System - Poor Practice.
Fig. 273. - Proper Drainage of the Range Boiler.
Special devices of merit are on the market, by means of which the sediment may be drawn off direct, without drawing off the contents of the boiler. In these devices, the water is taken into the cold-water range pipe from a point above the top of the collection of sediment.